multiplexer based temperature monitoring system


Thread Starter

jp shah

We have MTL 831/836 mux based system which is blind one. I want to connect suitable display to monitor all the temperature. Model MTL 836 is now obsolete. so I want guidance regarding suitable software and hardware for that.


How many temprature signals are you measuring? I faced a similar problem with an old & obselete MUX unit of an old & obselete(!) italian company. In the end we had to replace it all by a low cost PLC with 01 RTD Input and a few relays/contactors for multiplexing.


Anand K. Iyer

MTL has now come up with the 8000 series with Modbus connectivity. This allows, any SCADA or HMI supporting MODBUS to connect to MTL modules.

I have used it in one of my projects in the past and is easy to set up and use.

Of course there will be severalcompeting products available in the market, when you go to replace MTL and you wil be able to select from several of them.
1- How many temp. inputs in your MTL multipxer?
2- How do you switch one input to the output?
3- Is MTL 831/836 an active barrier? If yes it must be DC or AC powered.

I suggest that you can use a simple current loop indicator to monitor the 4_20 mA multiplexer output and a set of switches to choose which temp. to monitor.

If your display must be in an hazardous area (I guess this is the purpose of the MTL mux.) you will have to insert the display in a NEMA 7 (explosion proof) housing. Crouse Hinds is a good supplier for that type of housing. All wires must be then enclosed in ridgid conduit also.

Good luck.